An industrially advantageous process for producing 5,7-dichloro-4-hydroxyquinoline (DCHQ) useful as an intermediate for agrohorticultural bactericides. The process comprises (i) hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline into 5,7-dichloro-3-carboxy-4-hydroxyquinoline (DCQA) in the presence of hydrochloric, sulfuric or phosphoric acid and (ii) decarboxylating the formed DCQA into DCHQ in the presence of sulfuric or phosphoric acid. In particular, this process comprises continuously conducting the hydrolysis of 5,7-dichloro-3-ethoxycarbonyl-4-hydroxyquinoline and the decarboxylation of the hydrolyzate in the presence of sulfuric acid having a specified concentration. The invention also relates to a process for producing DCQA by hydrolyzing 3-cyano- or 3-ethoxycarbonyl-5,7-dichloro-4-hydroxyquinoline in the presence of hydrochloric, sulfuric or phosphoric acid and a process for producing DCHQ by decarboxylating DCQA in the presence of sulfuric or phosphoric acid.
一种具有工业优势的生产
5,7-二氯-4-羟基喹啉(DCHQ)的工艺,可用作农业园艺杀菌剂的中间体。该工艺包括:(i) 在
盐酸、
硫酸或
磷酸存在下,将 3-
氰基或 3-乙氧羰基-
5,7-二氯-4-羟基喹啉水解为 5,7-二
氯-3-羧基-
4-羟基喹啉(D
CQA);(ii) 在
硫酸或
磷酸存在下,将形成的 D
CQA 脱羧为 DCHQ。具体而言,该工艺包括在具有特定浓度的
硫酸存在下,连续进行 5,7-二
氯-3-乙氧羰基-
4-羟基喹啉的
水解和
水解产物的脱羧。本发明还涉及一种在
盐酸、
硫酸或
磷酸存在下通过
水解 3-
氰基或 3-乙氧羰基-
5,7-二氯-4-羟基喹啉生产 D
CQA 的工艺,以及一种在
硫酸或
磷酸存在下通过脱羧 D
CQA 生产 DCHQ 的工艺。